Common timing circuit



March 3, 1953 E. s. GIBSON 2,630,564

I COMMON TIMING CIRCUIT FiledSept. 15, 1950 2 SHEETS-SHEET 1 F/G. T0 Ann-mu I A407 /05 ,/04

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COUPLER m0. T0 Tuna/r150 I sewn/Iva AMPLIFIER C C 7- ll 7 I I ml I II II I I II I Cflflfl/YEL RELAY INVENTOR E S. GIBSON A ORNEY Patented .Mar. 3, 1953 COMMON TIMING omourr Earl S. Gibson, Ridgewood, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application September 13, 1950, Serial No. 184,619

This invention relates to alarm systems and has for its object the provision of-means for distinguishing between temporary and prolonged:

abnormal conditions.

In communication systems certain abnormal conditions may arise which may correct themselves after a short interval, but which if pro longed may require adjustment.

Where there are a number of pieces of equipment subjectto the same abnormal condition, but at different times, the provision of separate timing means for each piece of equipment is costly.

In accordance with the present invention means is provided, responsive to the occurrence of anabnormal condition on any piece of equipment, to connect that equipment witha common timing device and start a timing operation which results in the sounding of an alarm only if the condition persists beyond a predetermined time interval. i v

In accordance with a'fur'ther ieatin'e of the invention, means is provided for preventing the connection of the timing'device withan additional piece of equipment during the timing operation. x

if the abnormal condition is still'present at the end of the time interval a registration is :made of the identity of the piece of equipment "in which the. condition arose and reseizure by the identified equipment is prevented, while the timing device is made available to other pieces of equipment. A

More specifically the timing and valarm arrangement of the'present invention is. designed :for use in connection with radio channels sub- .ject to fading. To detect such fading a sensitrol:

relay is associated with each, channel, which is 'held operated as long as the radio currents are of sufficient strengthfWhen fading occurs the :sensitrol relay releases to seize the timing circuit. Since the current strength may be rising at the end of the measured time interval, auxiliary,

means is provided to reoperate the sensitrol relay at that time and to then test whether the relay is held operated before registering the fad-f Zing condition.

These and other features'of the invention will '11 Claims. (01. 343-200) ure a first time interval.

individual to the two channels and the common timing circuit.

This timing and alarm arrangement mat con-' veniently be associated with an alarm signaling system of the type shown in the application of Clutts-Pullis-Schenck-Weber, Serial No. 184,- 632, filed September 13, 1950, which issued on January 22, 1952,'as Patent 2,583,088 and was reissued on November 11, 1952, as reissue patent 23,571.

The operating winding Hill of sensitrol relay Hit is connected through fixed resistance I02 and adjustable resistance I03 by means of high frequency filter I04, tuned to the particular radio channel, transducer I05 and directional coupler N16 to the circuit over which the particular channel, which may be called channel 1, is connected to the radio antenna, indicated by wire Hi1. By similar means the operating winding I Hi oi sensitrol relay III is connected with the circuit over which another channel, which may be called channel X is connected to the radio antenna.

As long as radio waves of satisfactory strength are passing over wire I01, relay I00 holds its contact 168 open. When the signal strength fades, contact I08 closes and, if the timing circuit is normal, completes a circuit from ground over contact I08, conductor I09, contact I of relay 2%, contact 5 of relay 2! resistance 202,

lower winding of relay 20!, contact 3 of normally operated relay 293, contact 2 of relay 2104 to battery. Relay 20I operates and locks in a circuit from battery through its upper winding,

and over its contact 3 to ground at contact 3 of relay 204. Relay 2M also closes a second locking circuit for itself from ground over its contact 6, through resistance 202 and its lower winding to battery as above traced.

'Relay 2M in operating connects ground over its contact 1 to battery through the winding of relay 230 to seize the timing circuit and start its operation. Relay 230 when operated opens the circuit of relay 203 which releases slowly to meas- The release time of relay 203 is made sufiiciently slow so that, if the cause of fading affects other channels, for example channel X, the associated sensitrol relay ill may release to operate the corresponding timer seizing relay 251 and have the latter relay look before relay 203 opens its contacts.

When relay 203 opens its contact 3 no other channel may operate its timer seizing relay. At

its contact 4, relay 203 opens the shunt around timing condenser 205, permitting this condenser to charge in a circuit from +130-volt battery, resistance 206, condenser 205 to ground at contact 5 of relay 203. Condenser 205 is connected through resistance 2I2 to the control anode of tube 207, +130 volts to the main anode and ground over contact 5 of relay 203 and through the winding of relay 208 to the cathode.

When relay 203 closes its contacts I and 2, it connects ground from contacts 5 and l of relay 208 to conductors 209 and 2H). With timer seizing relay 20l operated, ground on conductor 205i is connected over contact 4 of relay 20L conductor 2, contact 2 of key I20 to battery through the reset winding of sensitrol relay I! causing that relay to reopen its contact. Similar circuits are closed for the reset windings of any other sensitrol relays which may have released and operated their associated timer seizing relays.

Condenser 205 and resistance 205 are so chosen that it, requires approximately six seconds for condenser 205 to charge to the breakdown potential of tube 201. When this charge is reached tube 201 breaks down and relay 208 operates. With relay 208 operated, ground is disconnected from. the reset winding of the sensitrol relay It! and that relay may hold its contact open or closed as determined by the transmission level in the associated channel.

Relay 205, in operating, closes a circuit to test whether the sensitrol, relay I0'I. has again opened its contact, this circuit extending from battery over contact I of relay 2 04, contact 6 of relay 208, upper winding of relay 200, resistance 2!], contact 2 of relay 2,0I conductor I09 to the contact I08 of relay I01. If this contact is closed, relay 200 operates, and lights lamp 22s to indi cate the channel on which the fading condition has occurred, closing a, locking circuit for itself from battery through its lower winding and over its contacts and- 2 to conductor I09 and ground supplied by relay IOI. At its contact I, relay 200 opens the operating circuit of relay 20I so that the timing circuit cannot be reseized by channel I until the fading; condition has ended.

Relay 200 closes a circuit from ground over contact I of relay 20I, contact 6. of relay 200, to battery through the winding of common. alarm relay 2I8. Relay 2I8 operates and looks over its contact 3 and the contact. of relay ZIQ to ground at contact 3 of relay 200-. Relay 2I8 lights lamp 220- and grounds conductor 22I to give an audible alarm when the station is at-' tended. Key 222 may be operated to operate relay 219 and release relay 218' to silence the alarm.

In addition relay 2.00.. atv its contact 4, connects ground to conductor 223- closing a, circuit through the lower winding of relay I2 I and over contact I of that relay to: battery supplied to conductor I22 by the station alarm sending circuit I23. Relay I2I locks to. battery over its contact 2 as long as conductor 223- is grounded and, also looks in a circuit from battery through its upper winding, resistance. I24, and. its contact 3 to ground supplied. to, conductor I25 by the indication sending circuit I25. Ground on conductor 223, also initiates. the operation of the station alarm sending circuit I23. to. send an alarm signal to an attendedstation, while ground supplied over contact 6 of relay I-2I- toqt-he indication, sending circuit.- l.26 is later used-to transmit the identity of the channel to the.- attended t n- A suitable station alarm sending cir cuit and indication sending circuit are disclosed: in the above-identified patent to .Clutts et al.

Relay 208, when operated as above described, opens the shunt around condenser 2 I3 permitting that condenser to charge in a circuit from +-volt battery, resistance 2, condenser 2I3, to ground over contact 3 of relay 208. Condenser 2I3 is connected through resistance 2I5 to the control anode of tube 2I6, +130 volts being connected to themain anode. The cathode of tube 2I6 is connected through the winding of relay 204 to ground over contact 3 of relay 208. Condenser 2I3 and resistance 2 are so chosen that it requires approximately 1.3 seconds for the charge on condenser 2I3 to reach the breakdown potential of tube 2I5 at which time the tube becomes conducting and relay 204 operates.

Relay 204. at. its contact I opens the operating circuit of relay 200 and similar relays pertaining to. other channels so that any subsequent closure of a sensitrol relay contact must go through a complete timing cycle before it may be registered. At its contact 3', relay 204 opens the holding circuit for relay 20!, permitting that relay to release. The release of relay 20] in turn releases: relay 23.0, which recloses the operating circuit-for relay 203. Relay 203 operates, opening the. operating circuit of relay 208 and reclosing the shunt. around condenser 205, to discharge the condenser and quench tube 201.

Relay 208 releases, opening the circuit. of relay 204 and reclosing the. shunt around condenser 2I3 to discharge the condenser and quench tube 2I6. With relay 208 released, the timing circuit is restored to normal. 7

Relay 200 may be. released by operating key I20 to energize the reset winding of relay IIII. When the keyis released. if the fade persists and contact I08 recloses, it will be treated as a new alarm.

When the station is unattended. and the indication sending circuit functions to transmit the trouble indication. to. an attended station, ground is connected to conductor I21 at a particular point in the transmitting cycle. Ground on conductor I2-I operates relay 225, in turn operating relay 22B. Relay 225 connects ground to conductor 221 to hold operated relay 200 and the corresponding relays of other channels which may be operated. Relay 226 connects ground to conductor 228 which isextended over contact I, of relay 200 to conductor 2| I to operate the reset windingv of relay I01. The. reset windings of sensitrol relays associated with other operated channel relays like. relay 200 are also operated. When-ground is removed from conductor I21, relays225and 226 release and, if relay I M holds its contact I08 open, relay 200 also. releases.

What is claimed is:

1. In a signaling system, a plurality of apparatus units subject to temporary abnormal conditions, a common timing circuit operable through a cycle to. measure a plurality of time intervals, means under the control of each apparatus unit responsive to an. abnormal conditionffor. seizing said common timing circuit and initiating its cycle of operation, and means operated by said timing circuit at the end of a pre determined one of said time. intervals to record an alarm.

2. In a signaling system. a plurality of apparatusv units. subject to.- temporaryabnormal conditions, a common timing circuit operable g5. through, Qycle: to. measure a plurality of time the identity of the seizing: unit and to operate labia-*- paratus units subject to temporary abnormal conditions, a common timing circuit operable through a cycle to measure a plurality of time intervals, means under the control of each apparatus unit responsive to an abnormal condition for seizing said common timing circuit and initiating its cycle of operation, means operated by said timing circuit at the end of a predetermined one of said time intervals to record the identity of the seizing unit and to operate an alarm, and means operated by said timing circuit at the end of a subsequent one of said time intervals to restore said timing circuit to normal.

4. In a signaling system, a plurality of apparatus units subject to temporary release in response to a trouble condition, a common timing circuit operable through a cycle to measure a plurality of time intervals, means under the control of each apparatus unit responsive to a temporary release for seizing said common timing circuit and initiating its cycle of operation, and means operated by said timing circuit at the end of a predetermined one of said time intervals to record the identity of the seizing unit and to operate an alarm.

5. In a signaling system, a plurality of apparatus units subject to temporary release in response to a trouble condition, a common timing circuit operable through a cycle to measure a plurality of time intervals, means under the control of any one of said apparatus units responsive to a temporary release for seizing said common timing circuit and initiating its operation, auxiliary operating circuits for said apparatus units means operated by said timing circuit at the end of a first one of said time intervals to close the auxiliary operating circuit for said seizing unit for a second one of said time intervals, and means operated by said timing circuit at the end of said second interval, in response to the rerelease of said unit to record the identity of the seizing unit and to operate an alarm.

6. In a signaling system, a plurality of apparatus units subject to temporary release in response to a trouble condition, a common timing circuit operable through a cycle to measure a plurality of time intervals, means under the control of each apparatus unit responsive to a temporary release for seizing said common timing circuit and initiating its cycle of operation, and means operated by said timing circuit at the end of a predetermined one of said time intervals to record the identity of the seizing unit, to operate an alarm, and to prevent said seizing unit from reseizing said timing circuit for the duration of said release.

7. In a signaling system, a plurality of apparatus units subject to temporary abnormal conditions, a common timing circuit operable through a cycle to measure a plurality of time intervals, means under the control of any one of said apparatus units responsive to an abnormal condition for seizing said common timing circuitandinitiating its operation, surna es; crating circuits for said apparatus units means under the control of'said timing circuit at the end of a first one of said time intervals to close 1 the auxiliary operating circuit for said seizing unit for a second one of said time intervals,

means operated by said timing circuit at the end of said second time interval to record the identity of the seizing unit and to operate an alarm, and means operated by said timing circuit at the end of a third one of said time intervals to restoresaid timing circuit to normal.

8. In a signaling system, a plurality of radio channels subject to fading, 'a common timing circuit operable through a cycle to measure a plurality of time intervals, means under the control of each channel responsive to a temporary fading for seizing said common timing circuit and initiating its cycle of operation, and means operated by said timing circuit at the end of a predetermined one of said time intervals to record the identity of the seizing channel and to operate an alarm.

9. In a signaling system, a plurality of radio channels subject to fading, a normally operated relay in each channel, said channel relays releasing in response to fading on the associated channel, a common timing circuit operable through a cycle to measure a plurality of time intervals, means responsive to the release of one of said relays for seizing said common timing circuit and initiating the operation thereof, auxiliary operating circuits for said channel relays, means operated by said timing circuit at the end of a first one of said time intervals to close said auxiliary operating circuit for the channel relay for a second time interval, and means under the control of said timing circuit after said second interval, operated if said channel relay has again released, to record the identity of the channel associated with said channel relay.

10. In a signaling system, a plurality of apparatus units subject to temporary release in response to a trouble condition, a common timing circuit operable through a cycle to measure a plurality of time intervals, means under the control of each apparatus unit responsive to a temporary release for operating a seizing relay individual to said apparatus unit, means under the control of one operated seizing relay to cause said common timing circuit to measure a predetermined time interval during which other apparatus units may operate the seizing relay individual thereto, means operated at the end of said predetermined time interval to prevent the operation of any additional seizing relays, auxiliary operating circuits for said apparatus units means under the control of said timing circuit at the end of said predetermined interval to close the auxiliary operating circuits for units Whose seizing relays are operated for a further predetermined interval, and means effective at the end of said further predetermined interval, if any of said units have again released, to record the identity of said released seizing units and to operate an alarm.

11. In a signaling system, a plurality of radio channels subject to fading, a normally operated relay in each channel, said channel relays releasing in response to fading on the associated channel, a common timing circuit operable through a cycle to measure a plurality of time intervals, means responsive to the release of any one of said channel relays for operating a seizing relay individual to said channel. means under the mmmtzqneronenat dseizineyelwfio: use e dz ure efl rstmd rrmines -t m ntwel. ur n icll her an- 11 2103 im n, .1mm w.

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of anyedditional s'eizing ne lays and to close an auxiliary?operating cirpuit for; the channel relay associated with-eahr operated seizing relay for a segond predeterminedihterval and means under theconjrol of. saidjiming; cirpuit aftger said sec- 0nd intevr-Val; eflepztgiye.if any, of, said, channel relays have again released, to regord the identity of the channels a 'ssoeiet ednwit h Said releasedehan 15v el rela s:-

GIBSON.

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